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m1" vsmme cert.

UNITED STATES PATENT OFFICE.

CHARLES H. TOXXDORFF, OF ST. LOUIS, MISSOURI, ASSIGNOR, BY DIRECT AND M15831) ASblUrNMENTS, TO HENRY KUHN AND THE M. A. SEED DRY PLATE C(HIPANY, BOTH OF SAME PLACE PH OTOG RAPHIC NEGATIVE-PLATE SPECIFICATION forming part of Letters Patent No. 375,231, dated December 20. 1887.

Applice mm filed March 29, 1886. Serial No. 197,012. (No model.)

To aZ Z whom it may concern:

Be it]; nown that I, CHARLES H. TONNDORFF,

of St. Louis, Missouri, have made a new andv useful Improvement in Photographic Nega- 1 The improvement is especially valuable in that it enables photographic neg. ttivc-plates to 2c be furnished to the trade and to users with an undeveloped vignette or border already in the plate-film, which vignette or border can, along with the picture produced by means of a second exposure within or atthe side of the vig- 2 nette or border, be ultimately developed upon the plate, and thereby obviate the need of employing a vignette apparatus at the time of printing the positive.

in carrying out the improvement I take 0 what is known to the trade as a dry-plate and expose it to the light underor in the rear of u elieh. or mask whose shape is complemental to thatolthe desired vignette or other improssion that is, to produce a vignette, a

cliche, suitably constructed at its periphery 5 to produce a vignette and of proper size and shape to cover the central portion of the tilin where the picture ultimately is to be taken is placed over or in front of the central portion of the dry-plate, and then the masked o plate is exposed to the light, in doing which care should be taken to let the light strike the plate at right angles in front. An exposure of a second or two is sulficient.

A cliche produetd by pllotn taphilnnnir 4 ods 1 consider the most desirable one to use, although other kinds-such, for instance, as stained glasscan be used with good results. To produce a border, or something having a sharp outline, a cliche having a correspond- 5o ing sharp outline is employed. The dryplates having the impression thus produced in the film are of course kept from the light until the time of the second exposure for taking the picture, when it is exposed in the ordinary 55 manner in the camera.

I claim As a new article of manutitcture, a phot'ographic negative-plate having an undeveloped vignette or border upon that partof the plate- 6 film which surrounds or partially surrounds the space to be occupied by the dcsi red pieturo.

\\itnesses:

(l. l). Moon'v, J W. Home. 

